Fix creation of nested directories for runlog/results

Currently, defining nested directories in model.props to store runlogs/results leads to an error if one of the parent directories has not be created manually before the simulation.

Example:

> model.props
...
# folder in which csv results are saved
104 results.folder = results/scenario1/usecase42
...

leads to an error if results/scenario1 has not been created manually, while usecase42 will be created by ModelIO.

Fix:

Using boost::filesystem::create_directories(destination_results); instead at model_io.cpp:110.

src/model/model_io.cpp

@@ -101,13 +101,13 @@ void ModelIO::init_logging() {
         boost::filesystem::path destination_results_edges(props->getProperty("results.folder") + "/cables/");
 
         /* create new folders in rank 0*/
-        boost::filesystem::create_directory(destination);
+        boost::filesystem::create_directories(destination);
         boost::filesystem::create_directory(destination_agents);
         boost::filesystem::create_directory(destination_behavior);
         boost::filesystem::create_directory(destination_edges);
 
         //result folders are created in any case
-        boost::filesystem::create_directory(destination_results);
+        boost::filesystem::create_directories(destination_results);
         boost::filesystem::create_directory(destination_results_agents);
         boost::filesystem::create_directory(destination_results_edges);